Bill Tortorello's Norway spruce was killed by a DuPont herbicide. The company has been slow to remove it from his yard in Fox Lake and pay compensation. (Dave Shields, Photo for the Chicago Tribune)

The herbicide was supposed to kill the weeds in Bill Tortorello's yard.

It did, but the chemical applied by Lawn Doctor of McHenry County in April 2011 didn't stop there.

In late May, the needles on Tortorello's 48-foot Norway spruce began turning brown.

A few weeks later, the tree was dead.

For Tortorello, it was a terrible blow. He and his wife bought their lot in Fox Lake 19 years ago and built their house in the shadow of the towering evergreen. For family picnics, he used to tie one end of a volleyball net to the tree's trunk and the other to the garage.

"We have pictures of the kids playing under the tree," he said. After it died, "we just felt terrible."

At the time, Tortorello had no idea what had happened. A local tree trimming company examined the evergreen and could not determine what killed it. An arborist was similarly perplexed.

It wasn't until mid-June that Tortorello learned the truth.

In a letter from the lawn care company, he was informed that Lawn Doctor had tested a new herbicide by DuPont called Imprelis. The herbicide had been field-tested by more than 25 major universities, including the University of Illinois, the letter said.

"This herbicide, while costing more initially, would have minimized the use of herbicides overall and seemed to be a good choice for our environment," wrote Rick Montreal, the owner of Lawn Doctor of McHenry and Lake Counties.

Turns out, Imprelis wasn't such a hot choice for the environment — or at least for certain varieties of trees. Nationally, thousands of trees were damaged or killed by the herbicide, which had a particularly devastating effect on Norway spruce and white pine.

Imprelis was removed from the market a year ago, after the federal Environmental Protection Agency issued a stop sale order Aug. 11, 2011. The EPA said in a news release that it is conducting an independent evaluation of the herbicide. The agency said the herbicide "poses a low risk to both humans and non-target terrestrial and aquatic organisms, except for plants."

After receiving notification that his tree likely had been killed by Imprelis, Tortorello called Lawn Doctor of McHenry County. He was told DuPont had taken responsibility for the damage Imprelis had caused, and that a claim process had been established.

DuPont was promising to remove and dispose of dead trees. It was also promising to replace those trees, or compensate homeowners for their losses.

In October, Tortorello filed a claim through Lawn Doctor of McHenry County, which then forwarded the paperwork to DuPont.

On Dec. 9, DuPont wrote Tortorello a letter acknowledging receipt of his claim.

In the spring, DuPont sent an adjuster to Tortorello's home. The adjuster determined that the tree was in fact dead, and that it had been killed by Imprelis.

Tortorello thought the process was moving along. Then things seemed to grind to a halt.

He said he called DuPont several times and was told each time that the claim would be resolved "soon." On each occasion, he was advised not to cut the tree down on his own, he said.

With the dead tree standing ominously in his front yard and no resolution in sight, Tortorello wrote a letter to DuPont's CEO on May 15.

"DuPont is exposing itself to additional liability if our tree falls and does further damage or injures someone due to your specific instructions not to cut down the tree," he wrote. "Hopefully you will be able to improve your claim process to get our claim as well as the many thousands of others settled."

In response, DuPont sent a form letter saying yet again that his claim would be resolved soon, he said.

Tired of waiting, Tortorello emailed What's Your Problem? on Aug. 22.

"The tree has now been dead for 15 months and we are concerned it may fall on our house," he said. "We do not understand what could possibly be taking DuPont all this time to resolve our claim."

Childress said she could not talk about Tortorello's claim specifically but said DuPont has received more than 33,000 claims from homeowners and golf course operators who think they have trees that were injured or killed by Imprelis.

"This is a complex process and it takes time to do it fairly and accurately," Childress said in the email.

So far, she said, DuPont has offered resolution agreements to about 50 percent of property owners who filed claims. The company plans to send proposed agreements to all remaining claimants this fall, she said.

"Resolution of Imprelis damage is a top priority for DuPont Crop Protection products," Childress said in the email. "We sincerely regret any damage or inconvenience that the use of Imprelis may have caused."

She said property owners who have an Imprelis-damaged tree and are worried that it has become dangerous should call DuPont at 866-796-4783.

"If a tree is found to be hazardous, we will make arrangements to remove it with the property owner's consent," Childress said.

Monday morning, a national tree removal company hired by DuPont called Tortorello.

"He said he received a rush order from DuPont," Tortorello said.

Exactly when the tree will be removed is unclear, but Tortorello said he was given the impression the tree could be cut down in the next week or two.

"That's the first step, which is the good thing, to get the tree down," he said. "The second step is to determine how much they're going to give us for the tree."

The Problem Solver will provide updates when Tortorello's tree is removed, and when he receives a compensation offer from DuPont.